/Engine/Source/Developer/ToolMenus/Public/ToolMenu.h
[UToolMenu](API\Developer\ToolMenus\UToolMenu) * AddSubMenu ( const [FToolMenuOwner](API\Developer\ToolMenus\FToolMenuOwner) Owner, const [FName](API\Runtime\Core\UObject\FName) SectionName, const [FName](API\Runtime\Core\UObject\FName) Name, const [FText](API\Runtime\Core\Internationalization\FText) & Label, const [FText](API\Runtime\Core\Internationalization\FText) & ToolTip )